You know those little ideas that "pop" into your head in the shower, waiting for an elevator, or in the middle of the night? They're called mind flares. Avoid "fizzling out" thoughts or they'll come back to haunt you later because you "forgot." Mind flares are rare, like shooting stars, and only streak across your brain periodically.
Even if you don't feel these flares are noteworthy, you should take precautions to preserve them:
Jot them down! Keep a notebook near your bed or use the Notes app on your phone (just don't attempt this while in the shower)
Share your wisdom. Talk through your ideas with trustworthy friends, colleagues, or family members to flesh them out (collaboration is sometimes essential to acting on flashes of genius)
Act. While jotting ideas down and sharing them with others is beneficial, it's imperative you act on them. Research the idea to make sure no one else came up with it first.
Trademark it! So, you wrote them down, shared them in confidence, and started acting on them. Now it's time to trademark your idea (or copyright it, depending on the medium). Legal Zoom is excellent for this.